It is generally known that the surface of a disc or record used in conventional electronic sound reproduction systems, which systems employ a motor driven turntable, tone arm and stylus, require that the surface of a record to be played be cleaned adequately to provide optimum reproduction of sounds recorded thereon and to maintain the stylus in optimum condition.
Recent advances in electronic and optical technology have resulted in the use of lasers as a means for transferring information to and from discs or records, i.e., recording or playing back information. Such systems are not limited to recording and playing back merely audio information, including music, but may also be employed as a means for storage and retrieval of video information. Such systems, known as digital systems, distinguishing them from analog record and tape systems, provide almost distortion-free sound reproduction and very high quality video reproduction. With such characterisitics, a laser information transfer system offers great potential to stimulate the home entertainment industry.
The records or discs used with these digital systems on which audio or video information is stored are known variously as digital discs, compact discs (CDs), digital audio discs, and grooveless digital discs. In contrast to conventional LP records in which the audio signal is mechanically detected from the record's groove by a stylus, a digital disc stores information by means of microscopic indentations or pits engraved in the reflective surface of the metal disc which are detected optically. A low power, narrowly focused laser beam is used to scan the rapidly spinning disc. The laser beam detects the minute indentations in the disc surface, transmitting the digital code to a digital/analog converter for conversion into an analog signal detected by a conventional amplifier. Since the optical laser system requires no direct contact between the objective lens of the laser and the disc surface for reproduction of information recorded on the disc, the surface of the disc is normally protected by a clear plastic layer, usually permanent and generally slightly greater than 1 millimeter in thickness. Although the laser beam is normally focused on the metal surface of the disc rather than on the plastic layer laminated thereto, dust and fingerprints are capable of causing some loss of efficiency of the system as a result of light scattering.
Heretofore, most record cleaning methods and devices which have been employed with analog type records have involved a manual cleaning procedure either before or after placement of a record on a turntable or the use of a device for cleaning a record after placement on a turntable. Several devices are known in the art in which an arm, pivotal at one end, has a cleaning pad or brush attached to the free end. In operation the pivotal arm is manually placed on the record. In another device, a brush or cleaning pad is attached directly to the tone arm of a record player. In each of these devices the record is cleaned during a playback mode. Such devices, although somewhat effective in cleaning a record or compact disc, are capable of exerting a drag on the disc rotating mechanism and thereby distorting the character of the information rendered in a playback mode.